Having covered aperture in a previous article, it feels natural to continue the digital photography tutorials by taking a look at another exposure related factor: shutter speed.
What is shutter speed?
Shutter speed is the setting that tells your digital camera how long to keep its shutter open and let light pass through to capture an image on the digital sensor. Combined with aperture, and luminosity (ISO), the shutter speed will determine your final exposure. The amazing thing about this mechanical setting is that, beside letting you create several cool photo effects, it’s the main tool used to capture motion in a still photo.
On your digital camera, the shutter priority mode is marked with an ‘S\' on the mode dial and it’s a semi-automatic exposure mode that lets you go for your desired speed while automatically setting the aperture accordingly for a final correct exposure.
Some cameras also have a ‘B’ (from bulb) setting available. This allows you to keep your shutter open for as long as you want to. There is, however, a catch because very long exposures come with increased image noise as a side effect. To avoid it, check if your digital camera has adjustable noise reduction and set that for long exposure shots when in ‘B’ mode.
Shutter speed, camera shake and sharper images
Shutter speed is measured in seconds (1, 2, 10, 30) and fractions of seconds (1/60, 1/125, 1/250, etc) – the smaller the number, the faster the speed. Under normal daylight conditions, the shutter speed will usually vary between 1/125th and 1/1000th of a second, which is fast enough to freeze movement and diminish the camera shake effects that would otherwise blur your photos.
Correct shutter speeds are always dependent on the available light at the moment you capture moments on your digital camera. Very long exposures (+2 minutes) in bright sunny days will result in extremely overexposed images while shooting the midnight sky using a very fast shutter speed (1/3200 sec) will give you a 100% black image.
There are times, especially in low light environments, when you have to use a slow shutter speed in which case a tripod, monopod or any other image stabilization tool comes in handy as they basically remove camera shake effects. Many modern digital cameras come with a built in vibration reduction (VR) option that serves the same purpose.
The one most important rule of thumb for safely shooting without a tripod is to choose a shutter speed equal or larger than the reciprocal of the focal length you use. For example, if you have a 50mm lens, 1/60 is the most you can go to be sure that your hand held taken photos won’t come out blurry.
Shutter speed and how to get cool photo effects
• Milky waterfalls
Image courtesy of idreamofdaylight
Image courtesy of David McNeary
A classic card shot of a waterfall is created with a slightly longer exposure, that gives the water a milky effect. Depending on what you want to suggest, a different shutter speed and a shorter exposure would make the water look sharper (as is in the second image)
• Freeze movement
Image courtesy of ZeePack
Always ask yourself what you want your images to say and freeze movement by using very fast shutter speeds. Sometimes, movement is the key of a great moment, in which case you no longer have to worry so much about shutter speed. It all depends of what the world looks like from behind the lens.
• Panning for speed
Image courtesy of Bertron8
By using a slower shutter speed (1/200), auto focus and panning your digital camera with objects in motion, you will be able to blur out backgrounds and give the impression of higher speed and increased dynamism in your shots. It takes a while to learn the panning trick, but the results are well worth it.
• Paint with light
Very long exposures (30 seconds in this case) in dark environments let you play with different light sources and ‘paint’ with light.
Always remember to experiment and try out various exposures. Through constant testing and repeating you will get to make the most of your camera and shutter speeds. Until next time, happy shooting!
Words Adela Trofin
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